public class Example4_7 {
  public static void main(String args[]){
   Battery nanfu= new Battery(100);
   System.out.println("南孚电池的储电量是："+nanfu.electricityAmount);
   Radio radio=new Radio();
   System.out.println("收音机开始使用南孚电池");
   radio.openRadio(nanfu);
   System.out.println("目前南孚电池的储电量是："+nanfu.electricityAmount);
  }
}
